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You are what you eat: Global and regional health effects of future food production under climate change

New study projects that climate change could lead to 500,000 diet-related deaths by 2050

March 3, 2016

by Daniel Mason-D'Croz

“An apple a day will keep the doctor away”- Proverb

“Let food be thy medicine and medicine thy food” – Hippocrates

Conventional wisdom has for millennia, if not longer, connected what we eat with our ability of living a healthy life. There is growing body of scientific literature that supports this conventional wisdom, directly linking what we eat and in which proportions to health outcomes, such as the prevalence of different types of cancer, diabetes, and cardiovascular diseases (See WHO report on Red Meat).

A changing climate poses unique challenges to the global food system, not only through changes in agricultural production, but also in how it will alter diets worldwide. Climate change threatens the global food system through increasing temperatures, changing precipitation patterns, and increasing weather variability, which will challenge farmers to produce enough to satisfy growing demands for food, livestock feed, and other uses. The consequences of these climatic shocks will effect regions and crops differently effecting consumer prices of food in diverse ways, which will complicate attempts by policymakers in formulating appropriate adaptation strategies. Some regions will be less impacted and then others. Nevertheless, the consequences of these changes will be seen not only on total food consumption and under-nutrition in the developing world, but in the quality of diets around the world.

To explore this question, a team of researchers from the University of Oxford and the International Food Policy Research Institute (IFPRI) worked together to assess the health effects of the changes in diet due to future climate change in a study just published in The Lancet. These efforts built on IFPRI’s IMPACT modeling system to assess the health consequences of changing diets. IMPACT, part of the Global Futures and Strategic Foresight project, is a global partial equilibrium model, that connects an agricultural economic model with biophysical models of crop growth, and water models to estimate the changes in production, demand, trade, and prices of agricultural commodities (See Robinson et al 2015). A series of climate scenarios were run in IMPACT to determine the potential changes in diet due to changing agricultural production and prices. These results were then used by Oxford’s Health model to assess the health consequences of these alternative diets, determining changes in the prevalence of non-communicable diseases and mortality.

This study found that climate change will slow progress on achieving global food security, decreasing food availability (measured in kilocalories) by approximately a third globally or by about 100 kilocalories per person per day. However, moving beyond just food supply the study also found that the changes in diet due to climate change, particularly due to reductions in the consumption of fruits and vegetables would have an even larger health impact than the change in food supply. In fact, a decline in food supply was not always associated with negative health outcomes, as the prevalence of obesity in high income countries decline, reducing the number of deaths by more than 260,000 in 2050. Nevertheless, these gains are more than offset by increasing under-nutrition in the developing world, and reductions in the consumption in fruits and vegetables worldwide. Overall, this study finds that if no climate change mitigation is achieved, more than 500,000 additional deaths are to be expected in 2050 due to the changed diets.